Gamma Amino Butyric Acid Attenuates Brain Oxidative Damage Associated with Insulin Alteration in Streptozotocin-Treated Rats.

The aim of the current study was to evaluate the role of γ-amino butyric acid (GABA) in insulin disturbance and hyperglycemia associated with brain oxidative damage in streptozotocin-treated rats. Streptozotocin (STZ) was administered to male albino rats as a single intraperitoneal dose (60 mg/kg body weight). GABA (200 mg/Kg body weight/day) was administered daily via gavages during 3 weeks to STZ-treated-rats. Male albino rats Sprague-Dawley (10 ± 2 weeks old; 120 ± 10 g body weight) were divided into 4 groups of 6 rats and treated in parallel. (1) Control group: received distilled water, (2) GABA group: received GABA, (3) STZ group: STZ-treated rats received distilled water, (4) STZ + GABA group: STZ-treated rats received GABA. Rats were sacrificed after a fasting period of 12 h next last dose of GABA. The results obtained showed that STZ-treatment produced hyperglycemia and insulin deficiency (similar to type1 Diabetes). These changes were associated with oxidative damage in brain tissue and notified by significant decreases of superoxide dismutase and catalase activities in parallel to significant increases of malondialdehyde and advanced oxidation protein products levels. The histopathology reports also revealed that STZ-treatment produced degeneration of pancreatic cells. The administration of GABA to STZ-treated rats preserved pancreatic tissue with improved insulin secretion, improved glucose level and minimized oxidative stress in brain tissues. It could be concluded that GABA might protect the brain from oxidative stress and preserve pancreas tissues with adjusting glucose and insulin levels in Diabetic rats and might decrease the risk of neurodegenerative disease in diabetes.

Effectiveness of Aloe vera on the antioxidant status of different tissues in irradiated rats.

This study was performed to evaluate the role of Aloe vera (Aloe barbadensis Miller) on the antioxidant status in different tissues of animals whole body exposed to 7 Gy gamma radiations, delivered as a shot dose. Aloe vera (leaf juice filtrate) was supplemented daily to rats (0.25 ml/kg body weight/day), by gavage, 5 days before irradiation and 10 days after irradiation. Experimental investigations performed 3, 7 and 10 days after exposure to radiation showed that Aloe vera treatment has significantly minimized the radiation-induced increase in the amount of malondialdehyde in liver, lungs, and kidney tissues of irradiated rats. Significant amelioration in superoxide dismutase (SOD) and catalase activities was observed from the 3rd up to the 10th days for lungs, on the 7th and 10th days for kidneys and at 10 days for liver. Data obtained showed that for the different tissues, improvement in the decrease of reduced glutathione (GSH) contents was obvious on the 10th day after irradiation. Treatment with Aloe vera was also effective in minimizing the radiation-induced increase in plasma glucose levels throughout the experimental period, while it has not ameliorated the increase in plasma insulin levels. It could be concluded that the synergistic relationship between the elements found in the leaf of Aloe vera could be a useful adjunct for maintaining the integrity of the antioxidant status.

Post-irradiation effect of Broncho-Vaxom, OM-85 BV, and its relationship to anti-oxidant activities.

This study was conducted to test the efficacy of Broncho-Vaxom (OM-85 BV) in rats after exposure to radiation-induced oxidative stress. Daily administration of Broncho-Vaxom (2.5 mg/kg/day) to rats for a period of 28 days produced a progressive significant increase in the activities of superoxide dismutase (SOD) and catalase in lungs and erythrocytes. No changes were recorded in reduced glutathione (GSH) content in lungs, while an increase was recorded in erythrocytes. Significant increase was also observed in serum gamma-globulin content. Intraperitoneal administration of Broncho-Vaxom to rats for 11 days before gamma-irradiation and daily during the period of irradiation, delivered as 1 Gy every other day to reach 9 Gy, significantly reduced radiation-induced lipid peroxidation (LPO) measured as thiobarbituric acid-reactive substances (TBARS) in the lungs and erythrocytes. Treatment with Broncho-Vaxom modified the radiation-induced decrease of serum gamma-globulins contents. It is postulated that Broncho-Vaxom, by enhancing the antioxidant system and increasing serum gamma-globulin content, could play an important role in modifying radiation-induced oxidative stress.

The modifying effect of beta-carotene on gamma radiation-induced elevation of oxidative reactions and genotoxicity in male rats.

The aim of the present work was to evaluate the modulatory role of beta-carotene on the radiation-induced changes in certain biochemical and cytogenetic parameters. beta-Carotene was given by gavage at a dose of 5 mg/kg body weight for 7 consecutive days before whole body gamma irradiation with 7 Gy (single dose). The levels of beta-carotene in plasma, thiobarbituric acid-reactive substances (TBARS) in plasma and liver, the activities of superoxide dismutase (SOD) and catalase in blood and liver were the selected parameters. Furthermore, the frequency of micronuclei (MN) of polychromatic erythrocytes (PCEs), normochromatic erythrocytes (NCEs), the ratio of PCEs/NCEs and the mitotic index (MI) of bone marrow cells were also evaluated. The biochemical and cytogenetic determinations were carried out 1, 24, and 72 h after radiation exposure. The results obtained revealed that administration of beta-carotene pre-irradiation significantly inhibited the decrease in plasma beta-carotene, significantly reduced the levels of TBARS in plasma and liver. Significant protection of the radiation-induced changes in the activities of SOD and catalase was also recorded in the blood and liver of beta-carotene-treated and -irradiated rats. beta-Carotene resulted in significant inhibition in the frequency of radiation-induced MN, as well as in the ratio of PCEs/NCEs and the MI of bone marrow cells. These results suggest that beta-carotene as a natural product with its antioxidant capacity and capability of quenching singlet oxygen, could play a modulatory role against the cellular damage affected by free radicals induced by whole body irradiation.